1. Field of the Invention:
The present invention relates to map data, a map data production method, a computer readable storage medium storing map data, and a navigation apparatus having map data.
2. Description of Related Art:
A KIWI format is known as a format of map data for navigation apparatuses (see Eiji FUJIMOTO, “Map Data Format KIWI for Car Navigation Apparatuses”, DENSO technical review, 2001, vol. 6, part 1, pp. 29-34). According to the KIWI format, the map data is constructed so that a map record target area (an area covered by a map) is divided into multiple meshes. Data about a road component and data about a background component are integrated on a one-mesh-by-one-mesh basis. In the above, the road component and the back ground component are components of the map.
In the case shown in FIG. 7, the data about a road component and the data about a background component are integrated into multiple data elements in units of mesh, so that the multiple data elements are made into multiple data files. In this case, since the multiple data files form the map data, the map data covering a large area results in a huge number of data files in accordance with the number of meshes.
When the map data has a huge number of data files, it takes a considerable amount of time to install the map data on a hard disk drive due to the huge number of data files.
In recent years, a navigation apparatus including a hard disk drive having map data is becoming popular. In manufacturing this type of navigation apparatus, it is necessary to transfer (install) map data on a hard disk drive of the navigation apparatus. A considerable amount of time required for this kind work is disadvantageous.